Optical lithography using projection or direct printing of a mask pattern has been the standard technology for fabricating patterned electronic devices. The size of the components produced depends on the ability of the optics to produce very small images in photo resist or mask materials. This is ultimately limited by the wavelength of the radiation used for exposure. In addition, this method only produces a pattern and not a device.
Various optical or electron beam writing approaches have been developed where a small, focused electron or electromagnetic beam is scanned over the surface of a photo resist, affecting a chemical change in the resist material so that it can be removed by subsequent chemical processes. Alternatively, the resist material may remain in place after subsequent chemical processing. The problem with this method is that there are feature size limitations and cost problems.
In yet another method, a small stylus such as an atomic force microscope (AFM) probe has been used to transfer a small amount of chemical to the surface to be patterned, leaving a very small (tens of nanometers) feature on the surface. This method is limited to the chemicals used and the mechanics of the probes themselves.
An object of the present invention is to provide a method to directly fabricate nanoscale electronic devices without using a mask.
Another object of the present invention is to provide a method that creates smaller mask features without using a mask.
Another object of the present invention is to produce a chemical pattern on a substrate for further build-up of multilayered films.